Neuroanatomy

Question 1

What are the 2 main cell types of the CNS?

Answer 1

neurones and glial cells

Question 2

Name the 4 major types of glial cells.

Answer 2

astrocytes
oligodendrocytes
microglia
ependymal cells

Question 3

Which cell type is more numerous in the CNS?

Answer 3

glial cells more numerous than neurones

Question 4

Role of astrocytes?

Answer 4

support, maintaining BBB and environmental homeostasis

Question 5

Role of oligodendrocytes?

Answer 5

produce myelin in CNS

Question 6

Role of microglia?

Answer 6

immune monitoring and antigen presentation

Question 7

Describe ependymal cells.

Answer 7

ciliated cuboidal/columnar epithelium that line the ventricles

Question 8

Describe the resting and activated state of microglial cells.

Answer 8

resting: elongated nucleus and short, spiny cell processes
activated: rounder and similar appearance to macrophage

Question 9

Which matter contains most neurones, cell processes, synapses and support cells?

Answer 9

grey matter

Question 10

Which matter contains axons and their support cells?

Answer 10

white matter (medullary centre)

Question 11

Which lobe lies anterior to the central sulcus and superior to the lateral sulcus?

Answer 11

frontal

Question 12

Which lobe is posterior to central sulcus, superior to lateral sulcus and anterior to parieto-occipital sulcus?

Answer 12

parietal

Question 13

Which lobe is posterior to a line from the parieto-occipital sulcus to the pre-occipital notch?

Answer 13

occipital

Question 14

Which lobe is inferior to lateral sulcus and anterior to the parieto-occipital sulcus line?

Answer 14

temporal

Question 15

Which lobe is normally hidden and important in a patient’s experience of pain?

Answer 15

insular lobe / insula

Question 16

Name the two nerve plexuses in the walls of the gut and which nervous system are they part of?

Answer 16

enteric nervous system 
myenteric plexus (between outer layers of SM)
submucosal plexus (in the submucosa)

Question 17

Which artery supplies the majority of the lateral surface of the cerebral hemispheres?

Answer 17

middle cerebral artery

Question 18

Which artery supplies the medial aspect of the frontal and parietal lobes?

Answer 18

anterior cerebral artery

Question 19

Which area of the brain does the posterior cerebral artery supply?

Answer 19

inferior aspect of cerebral hemisphere and occipital lobe.

Question 20

The name for the spinal cord terminating in a tapered shape?

Answer 20

conus medullairs

Question 21

The spinal cord continues as thin connective tissue cord (name?) which anchors it to the dorsal of the coccyx.

Answer 21

film terminale

Question 22

What is the spinal cord suspended by? It is found on the lateral surfaces of the cord - what it is formed by?

Answer 22

denticulate ligament

formed of pia & arachnoid tissue - attaches to dura at points along the length of the cord

Question 23

What does white matter contain?

Answer 23

longitudinally orientated nerve fibres (axons)
glial cells
blood vessels

Question 24

What are the subdivisions of the white matter?

Answer 24

posterior, lateral and anterior funiculi - each have a variety of fibre sizes

Question 25

What does grey matter contain?

Answer 25

neuronal soma, cell processes, synapses, glia and blood vessels

Question 26

What are the sections of grey mater?

Answer 26

left and right posterior horns left and right anterior horns (H) horizontal part of H =dorsal and ventral grey commissures which surround the central canal

Question 27

Which spinal segments would contain lateral horns of grey matter?

Answer 27

T1-L2

Question 28

Describe the arterial supply of the spinal cord.

Answer 28

3 major longitudinal arteries (1 ant. 2 post.) - originate from vertebral arteries Segmental arteries - from vertebral, intercostal & lumbar arteries. Radicular arteries - follow the dorsal and ventral roots - exit spinal cord at each level.

Question 29

In the spinal canal what is found between the dura and bone and what does it contain?

Answer 29

Epidural space - contains adipose tissue and the anterior and posterior venous plexuses

Question 30

Why is there less white matter in the spinal cord as you descend it?

Answer 30

it delivers axons to the brain so the further away it is from the brain, the smaller the proportion of white matter vs. grey matter

Question 31

Which spinal tract is responsible for fine touch and proprioception?

Answer 31

dorsal column / medial lemniscus system

Question 32

Where is the 1st order neurone of the dorsal column/medial lemniscus system?

Answer 32

in nucleus gracilis of medulla

Question 33

How do the fibres travel up the dorsal column?

Answer 33

enter spinal cord and ascends until they cross in the medulla, travel up to thalamus and synapse in the primary somatosensory cortex

Question 34

which fasiciuli of the dorsal column correspond to arms and which to legs?

Answer 34

arms - fascicles cuneatus | legs - fascicles gracilis

Question 35

Which tract carries pain, temperature and deep pressure?

Answer 35

spinothalamic tract | aka. anterolateral tract

Question 36

How do the fibres cross in the spinothalamic tract?

Answer 36

cross segmentally - enter spinal cord at posterior horn and synapse - axon crosses into contralateral anterior with matter and ascends to thalamus.

Question 37

How does information from the motor cortex reach the motor neurone?

Answer 37

via descending spinal cord tracts - the corticospinal tracts (lateral and ventral)

Question 38

What is the corticospinal tract responsible for?

Answer 38

fine, precise movement, especially in distal limb muscles

Question 39

What visible feature does the CST form?

Answer 39

visible ridges (pyramids) on the anterior surface of the medulla - hence pyramidal tract name.

Question 40

What percentage of fibres cross the pyramids at the medulla?

Answer 40

85% cross and the rest continue down ipsilateral side of spinal cord

Question 41

What is the term for the fibres crossing in the caudal medulla?

Answer 41

decussation of the pyramids

Question 42

What is decorticate posturing?

Answer 42

spastic paralysis of the corticospinal tract with hyperflesion of the upper limbs - a consequence of CVA of the internal capsule

Question 43

What are the 3 tracts of the "extra-pyramidal system"?

Answer 43

Tectospinal tract Reticulospinal tract Vestibulospinal tract

Question 44

What is the tectum?

Answer 44

the posterior portion of brain - mediates reflex head and neck movements due to visual stimuli

Question 45

Where does the tectospinal tract supply and where does it cross?

Answer 45

Motor input to cervical segments crosses midline then projects down spinal cord to C level synapse in anterior horn of cord

Question 46

Which extra-pyramidal tract influences voluntary movement?

Answer 46

reticulospinal

Question 47

What do fibres originating in areas of reticular formation (P&M) control?

Answer 47

pons - flexor movements | medulla - extensor movements

Question 48

What input does the vestibulospinal tract facilitate?

Answer 48

excitatory input to 'antigravity' extensor muscles | e.g. finds balance after pushed

Question 49

What is the consequence of lateral semi-section of spinal cord?

Answer 49

Brown-Sequard's syndrome - > ipsilateral paralysis - > ipsilateral hyperreflexia & extensor plantar reflex (CST) - > ipsilateral loss of vibratory sense & proprioception (dorsal column) -> contralateral loss of pain & temperature (spinothalamic)